Pumping apparatus



H. c. HUMPHREY Sept. 10, 1963 PUMPING APPARATUS Filed July 24, 19617271115111111 rlfifivlzlzlzzzllrlrr 7,11,12,11,? 11/27195545555?!155,455$141556 I!!! I71:55:55,951!!! lllllll/III/lflll/IrII/lUnited States Patent 3,103,175 PUMPING APPARATUS Howard C. Humphrey,Liberty, Tex., assignor to Texaco Inc., New York, N.Y., a corporation ofDelaware Filed July 24, 1961, Ser. No. 126,111

6 Claims. (Cl. 103-46) This invention relates generally to petroleumproduction and, inone specificc aspect, to a hydraulic oil well pumpingsystem for use particularly in the pumping of deep producing wells. 1

Among the, advantagesof subsurface hydraulic pumping is that the use ofsucker rods, with its attendant problems of rod breakage, wear,counterbalance and the like, is eliminated. Furthermore, with theprovision of a central installation, hydraulic power is available forthe pumping operation of a number of wells of varying depths and atvarying distances from the source of hydraulic power.

The bottom hole pump for subsurface hydraulic pumping, referred to as aproduction unit, includes a hydraulic engine connected directly to adisplacement pump. The engine consists of a reciprocating piston whosemotion is controlled by a hydraulically actuated valve and which isdriven and lubricated by power oil transmitted from the surface to theengine in the well.

The pump, at the lower end of the production unit, comprises areciprocating piston connected directly to the engine piston. The pumpintake is at the bottom end of .the. production unit and its dischargeis drawn off by production tubing.

. Since the power fluid used to operate the production unit is crude oildrawn off from a surface tank battery, it is feasible to allow the poweroil exhaust from the engine to be discharged into the pumped productionfluid.

Although prior art subsurface, reciprocating piston type a moreefilcient subsurface production unit.

It is another object of the invention to provide a simple pumpingapparatus which requires minimum upkeep and care for proper pumpingoperation.

Still another object of the invention is to provide a simple pumpingsystem for deep producing wells which is efficient yet requires aminimum of maintenance.

These and other objects, features and advantages of the invention willbe apparent from the following description and claims when read inconjunctionwith the accompanying drawing wherein:

FIG. 1 is a diagrammatic partial showing of the installation for usewith the present invention; and

FIG. 2 is an enlarged diagrammatic showing of the production unit.

The invention comprises reciprocating interconnected pump and powerpistons, with pressurized fluid used for actuating the power piston fordelivery of production fluid, the return of the power piston to originalposition comprising the intake pumping stroke for the production fluid.

I Referring to FIG. l of the drawing, the surface installation comprisesa low pressure, power oil supply source or tank 1%, receiving arelatively small volume of oil released by the transmitter (not shown),a power oil line at 111 leading to pump 120, whence the power oil isdelivered under pressure by line 13-!) leading from the pump to the highpressure power oil supply tank, indicated at 140, which not only holdsthe pressurized power oil but also a gas cushion indicated as 141. Thepower .oil leaves tank through pipe 142, passing through the intermitterat .150, which controls the direction of flow of the power oil and isshown diagrammatically simplified as a two way valve. After leaving the,intermitter, the power oil passes through pipe 10, (as shown herein)which is joined to power oil line tubing 11 at the casing head 12,closing the top of a producing well, with the production fluid, e.g.crude oil, being led off by production tubing discharging into a stocktank, as at 170.

A well hole 20, leading to the producing formation 21, is provided witha casing 22 held in position as by cement at 23. A string of productiontubing 13 is shown suspended in the well, joined to power :oil linetubing 11 in a manner known in the art and held in position by thecasing head 12 and spaced from the casing 22. The well production unit14 is shown disposed at the lower end of the power oil line tubingstring, which forms the housing for the power piston and pump plunger,and is joined to the production tubing at its lower end, and also isspaced from the casing. The production unit 14 is actuated by the poweroil provided through the power oil line tubing 11.

Referring to FIG. 2, showing the production unit 14 in enlarged form,there is disclosed, diagrammatically, a bumper block 30, e.g. aspring-loaded shock absorber, seated in the power oil line tubing 11.This bumper block is perforated at 31 to allow flow of power oil and isused as a stop on the return stroke of the power piston 32, which isjoined in spaced relationship to the pump plunger 33 by means of thepiston rod 34. A packing gland at 35 surrounds piston rod 34 andprevents any production fluid from leaking past the pump plunger. Thevent in tubing 11 at 35a is to equalize the pressure on the plunger 33,viz. to avoid building up pressure or a vacuum between the packing glandand the plunger.

Adjacent and shown parallel to the power oil line tubing 11 is theproduction fluid tubing 13 interconnected through duct means definingthe delivery passage at 36 and the by-pass port at 37. The inlet valvefor the production or well fluid is shown at 38 and the exhaust valvecontrolling its passage into the production tubing is shown at 3?. Thesevalves are shown diagrammatically and in use would be caged. The use ofa loading spring, indicated generally at 43, seated in the power oilline tubing 11 between the power piston 32 and the packing gland 35, foradditional control of the return of the power piston and pump plunger,is optional.

The operation of the pumping process will now be described briefly. Thepower stroke of the production unit begins with the supply of power oilfrom the surface through the tubing 11 to the passage 31, forcing thefree power piston 32 and so the pump plunger 33 downward to close theintake check valve 38 and to eject the production fluid from theproduction fluid chamber 15, defined in the tubing 11 between the pumpplunger and the check valve at 38, through the exhaust check valve at 39into the production tubing 13, up to the surface past the back pressurecontrol means 161 in tubing 160 and then into the stock tank 170. Z

At the same time, production fluid retained within the power line tubingbetween the power piston 32 and the packing gland 35 is forced outthrough the passage 37, which is in open communication at all timesbetween the power oil tubing 11 and the production tubing 13.

On the upstroke of the power piston 32 in the tubing 11 and so theintake stroke of the pumping cycle, the pressure of the production fluidupstream of the; bumper 30 is lowered by cut-off of the intermitterat'150, that is, the flow of pressurized power oil is shut off and thepower oil which is in the power tubing 11 is permitted to flow backthrough the pipe into the low pressure, power oil supply tank 100through the pipe line 180. This reversal of flow is possible because thehydrostatic head of the production fluid in the tubing 13, together withthe loading spring 40, are suflicient to force the piston upward on itspumping stroke, thereby discharging the power oil into the low pressuresupply tank at 100, the hydrostatic pressure in tubing 13 also closingthe check valve at 39. The succeeding downstroke of the power piston isproduced when the intermitter cuts oil the flow of the low pressurefluid from the power tubing 11 and permits pressurized power oil fromthe tank at 140 to pass through the pipe 10 into the power tubing 11.

The length of the power stroke is variable and is determined by theintermitter, which is regulated to produce the amount of productionfluid desired, ie the allowable, or to obtain a stroke to produce themaximum amount of well fluid possible. In addition, the produced fluidis relatively gas-free, for with the intake 14 to the production unitextending below the surface of the fluid in the well bore, the releasedgas would pass up in the annulus between the tubings 11 and 13 andcasing 22 and would be bled off through the conduit 24 with controlvalve 25 therefor. Also, two or more of these production units can beplaced in series.

-Due to the proximity of the sources of supply, the hydraulic fluid usedherein has been disclosed as power 01 Thus there has been shown anddescribed an improved deep well production system which is simple toconstruct, economical to use, and has a minimum of Working parts torequire maintenance.

The present application is a continuation-in-part of my co-pendingapplication, Serial No. 783,245, filed December 29, 1958, now abandoned.

Other modifications and variations of the invention, as hereinbefore setforth, may be made without departing from the spirit and scope thereof,and therefore only such limitations should be imposed as are indicatedin the appended claims.

I claim:

l. A free piston pump for a producing well having a casing and withpower fluid tubing and production tubing positioned in said producingwell and spaced from said casing thereof comprising the combination of apair of spaced imperforate pistons housed in said power fluid tubing,rod means interconnecting and spacing said pair' of imperforate pistonsfrom each other, inlet means for production fluid leading to said powerfluid tubing and located below one of said pair of pistons and includinga check valve which opens when said pistons move on an intake stroke andcloses when said pistons move on a discharge stroke, duct meansestablishing communication between said power fluid tubing and saidproduction tubing, one of said duct means being in open communication atall times between said production tubing and said power fluid tubingleading to the chamber therein between said pistons'and another or saidduct means being located adjacent said inlet means, and dischargecontrol means comprising a second check valve which opens when saidpistons move on a discharge stroke and closes when said pistons move onan intake stroke and being located adjacent said another of said ductmeans adjacent said inlet means.

2. In the pump as defined in claim 1, a packing gland surrounding saidrod means interconnecting said imperforate pistons and being positionedin said power fluid tubing below said one of said duct means and sealingsaid power tubing against the flow of production fluid past said packinggland.

3. In the pump as defined in claim 2, said power fluid tubing having anopening in the wall thereof located below said packing gland surroundingsaid rod means and above the uppermost position of said one of said pairof pistons, said power fluid tubing and said production tubing beingparallel to each other.

4. In a production unit for subsurface pumping for dischargingproduction fluid into production tubing having a valve housed thereinfor checking reverse flow of said production fluid, the combination ofan imperforate power piston and an imperforate pump plunger spaced fromeach other, a piston rod interconnecting said power piston and said pumpplunger, a packing gland surrounding said piston rod, power fluid tubinghousing said piston and said plunger and providing power fluid forlinear movement of said power piston and so a corresponding movement ofsaid pump plunger, an inlet valve for production fluid and with saidpump plunger defining a chamber for production fluid having dischargemeans into said production tubing adjacent said valve housed therein,said production tubing having open communication with said power fluidtubing through duct means ending adjacent said packing gland and leadingto the chamber in said production fluid tubing between said piston andsaid pump plunger whereby production fluid under hydrostatic pressureacts on said power piston on the pumping intake stroke. 1

5. In the production unit as defined in claim 4, resilient means spacedbetween said power piston and said packing gland in said power fluidtubing for additional control of the intake stroke of the pumping cycleof said production unit.

6. In combination with a subsurface pumping appara tus for dischargingproduction fluid into production tubing having a check valve againstreverse flow of said pro duction fluid and comprising a production unitof an imperforate power piston and an imperforate pump plunger spacedtherefrom, a piston rod interconnecting said power piston and said pumpplunger, a packing gland surrounding said rod and power fluid tubinghousing said piston and said plunger and providing power fluid forlinear movement of said power piston and so a corresponding movement ofsaid plunger and a'check valve located in said power fluid tubing anddefining with said pump plunger a chamber therewithin, said productiontubing being joined to said chamber and said check valve in saidproduction tubing being located adjacent said chamber, the improvementcomprising a power fluid circuit joined to said power fluid tubing forproviding power fluid thereto, and including sources of low pressure andhigh pressure power fluid and interconnecting pressurizing means and avalve means joining said power fluid circuit to said power fluid tubingfor connecting said sources in turn with said power fluid tubing wherebyhigh pressure power fluid is directed against said power piston for thedischarge stroke of the pumping cycle and at the end of said dischargestroke said high pressure fluid acting against said power piston beingreleased to the source of low pressure power fluid through said valvemeans, said production unit including resilient means spaced betweensaid power piston and said packing gland around said rod in said powerfluid tubing, said production tubing having open communication with thechamber between said piston and said plunger in said power fluid tubingadjacent said packing gland whereby production fluid under hydrostaticpressure acts on said power'piston on the intake stroke of the pumpingcycle.

References Cited in the file of this patent UNITED STATES PATENTS2,014,613 Ceverha Sept. 17, 1935 2,095,602 Huff Oct. 12, 1937 2,122,823Overall July 5, 1938 2,185,727 Emmons Ian. 2, 1940 2,376,538 Hardey May22, 1945

1. A FREE PISTON PUMP FOR A PRODUCING WELL HAVING A CASING AND WITHPOWER FLUID TUBING AND PRODUCTION TUBING POSITIONED IN SAID PRODUCINGWELL AND SPACED FROM SAID CASING THEREOF COMPRISING THE COMBINATION OF APAIR OF SPACED IMPERFORATE PISTONS HOUSED IN SAID POWER FLUID TUBING,ROD MEANS INTERCONNECTING AND SPACING SAID PAIR OF IMPERFORATE PISTONSFROM EACH OTHER, INLET MEANS FOR PRODUCTION FLUID LEADING TO SAID POWERFLUID TUBING AND LOCATED BELOW ONE OF SAID PAIR OF PISTONS AND INCLUDINGA CHECK VALVE WHICH OPENS WHEN SAID PISTONS MOVE ON AN INTAKE STROKE ANDCLOSES WHEN SAID PISTONS MOVE ON A DISCHARGE STROKE, DUCT MEANSESTABLISHING COMMUNICATION BETWEEN SAID POWER FLUID TUBING AND SAIDPRODUCTION TUBING, ONE OF SAID DUCT MEANS BEING IN OPEN COMMUNICATION ATALL TIMES BETWEEN SAID PRODUCTION TUBING AND SAID POWER FLUID TUBINGLEADING TO THE CHAMBER THEREIN BETWEEN SAID PISTONS AND ANOTHER OF SAIDDUCT MEANS BEING LOCATED ADJACENT SAID INLET MEANS, AND DISCHARGECONTROL MEANS COMPRISING A SECOND CHECK VALVE WHICH OPENS WHEN SAIDPISTONS MOVE ON A DISCHARGE STROKE AND CLOSES WHEN SAID PISTONS MOVE ONAN INTAKE STROKE AND BEING LOCATED ADJACENT SAID ANOTHER OF SAID DUCTMEANS ADJACENT SAID INLET MEANS.